Hydrocephalus is a condition where cerebro-spinal fluid builds up in the cavities of the brain, resulting in increased pressure on the brain and surrounding tissues. Atlhough it largely occurs in children, it's onset can occur at any age, although it is very rare in adults. Although it rarely causes death, it commonly causes brain damage.
In almost every case, the condition is caused when the natural ducts that allow CSF to drain into the rest of the central nervous system become blocked, often due to a congenital defect. Because the pressure can vary widely depending on the nature and extent of the blockage, symtoms may range from mild to severe. It most commonly presents with headaches, nausea, vomiting and sleepiness. If untreated, it can progress to herniation of the cerebellar tonsills or compression of the brain stem, then to coma.
Because the skull of infants remains soft several months after birth, hydrocephalus causes a swelling of the skull in its softer sections, resulting in a greatly enlarged head. Other symptoms typical in infants are eyes that appear to gaze downwards, seizures and separation of the bony plates of the skull.
However, hydrocephalus can also occur in older children, where if often presents with a brief high-pitched cry, changes in mental function, changes in facial appearance and difficulty controlling the eyes.
Treatment is generally to insert a surgical shunt to allow the fluid to drain into the spinal column.